Humidifier



May 29, 1951 B. M. MILLS 2,554,867

HUMIDIFIER Filed Aprll. 9, 1949 2 Sheets-Sheet 1 72062230? I ,Beflirazzz I72 i7ia'ids' B. M. MILLS HUMIDIFIER May 29, 1951 2 Sheecs-Sheet 2 Filed April 9, 1949 la War flerirezzafi Wild;

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Patented May 29, 1951 UN [TED .5 TA TE S I :HUMIDIFIER lBertram.- M...Mills,

Pawtucket, R...I., .assignor to The StandardEngineering' Works, IPawtucket, 'R.-I.,"a; corporation of Rhode Island ApplicationAprilr9, 1949, Serial'No. 86,515 J6 Claims. Cl. 261-91) This invention pertains to humidifiers of the type in which cold (unheated) water or .other liquid is atomizedor reduced to the form of "a vapor bymechanical or equivalentmeans, the finely divided moisture particles then being adiabatically absorbed by the air into which the vapor is delivered. While, for convenience in illustration, the invention .-is here disclosedtas embodied in apparatus ofthe industrial type (such as is used for:moistening the air .in :textile mi1ls, etc.), .it is equally useful when embodied in a humidifier, whether ornot portable, for use in homes or offices andwherein .the atomizing elements areusually housed ina cabinet or casing of ornamental external appearance. The invention disclosed constitutes an improvement upon-the devicedisclosed, .f.0r..example, in thepatent to Mills, No. 1,815,951, July 28, 1931.

Humidifiers, such as shown in the above patent, have proven very efi'ective and .have gone into extensive commercialuse. Howevenit has been noted that the moisture .laden air current does not emerge from the device .in a wayv to insure immediate contact with .aslarge a volume of the room air as is desirable for completeabsorption and, thus, under certain atmospheric conditions, moisture inthe form of minute droplets may be deposited on surrounding surfaces. Furthermore, as respects humidifiers designed for home or office use, it has been noted-that they have a tendency to emit an undesirable noise, not particularly loud but which is objectionable to some people. Careful study of apparatus built in accordance with theabove patent appears to indicate that there is a very substantial loss .of energy and capacity due to the friction of the flowing moisture laden air against the inner surface of the casing. The constructions shown in said patented device is such as to create a pronounced swirl-or rotating current in the moisture laden air which emerges from the vapor-creating means and this swirl probably accounts for the noise.

It has now been discovered, as the result .of extended practical experienceand after long experimentation, that-greatly improved results are obtainable by fixing thevanes which are impinged by the liquid-and which reduce the latter to the vaporform, at a very definite angle, within a very limitedrange.

It has also been noted that unless the undersurface of the atomizing disk be located very accurately with reference tothe-atomizing vanes, the effectiveness of the deyicesis greatly areduced. The possibility of inaccuracy of relative sonsnot well qualified to set up the apparatus with the requisite accuracy.

One object of the invention is to provide a humidifier of the general type disclosed, for-example, in the'above patent, but so improved as to insure a high velocity. of delivery and an improved quality of the moist air delivered, with consequent better-distribution and more thorough absorption of..the moisture by the ambient air. A further object isto provide'a humidifier of the above type so designed as to reduce the friction losses within the casing of the apparatus, thus increasing the capacity of the device. A further object is-to provide a humidifierso de signed as to reduce the tendency of the moisture ladenair, emerging from between the atomizing vanes, to take up a rotating or swirling motion within. the casing. Aiurther object is to provide a humidifier .so designed that the moisture laden air emergesin a substantially uninterrupted stream. A further object is to provide ahumidifier whose parts are so designed that,

in assembling them, the water-distributing surface of the atomizing disk must-be located accurately with respect to the atomizing vanes.

A further object is to provide 'a humidifier of the above type wherein the atomizing vanesare so designed as to provide approximately radial channels which terminate outwardly beyond that peripheral surface of the cover-member of which the vanes. constitute integral parts. A further object :is to provide a humidifier wherein the atomizing vanes are disposed at angles such as have been found to result in the optimum atomizingaction. Other and further objects .andadvantages of the inventionwill be pointed out in the following more detailed description and by reference to the accompanying drawings where- 1n:

Fig. -1 .is a diagrammatic side elevation of an industrialinstallation embodying the present inyention;

. Fig. 21's a-diametrical vertical section, to larger scalethan Fig. 1, showing .the constructionxof the atomizer, per .se;

.Fig. 3 is a verticalssection on the-same plane :as Fig.2, but to largerscale, showing the atomizing disk and the cover member with its atomizing-vanes;

Fig. 4 is a plan view of the parts shown in Fig. 3, a portion of the cover being broken away;

Fig. 5 is a fragmentary plan view, to larger scale, illustrating a desirable angular arrange ment of the vanes;

Fig. 6 is a fragmentary vertical radial section, to larger scale, substantially on the line 3-6 of Fig. 1, through the upper portion of the side wall of the fluid receptacle and the lower part of the case; and

Fig. 7 is a fragmentary diametrical section through the central portion of the atomizing cone and disk.

Referring to the drawings, the numeral 1 designates an atomizing apparatus of industrial type embodying the present invention. As illustrated, the atomizing mechanism is carried by a bracket 2 designed to be secured to a vertical surface, for example the wall of a mill or a supporting column. Liquid, usually water, is supplied through a, pipe 3, preferably passing through a strainer 4 and a pressure-reducing valve 5 to a float valve reservoir F from which it flows by gravity to the fluid receptacle of the humidifier. An overflow pipe 6 may be provided leading to a suitable discharge point. A flexible electrical conductor 1 extendsfrom' the motor of the humidifier to a conveniently located control box 8 which receives current through a conductor 9 from a suitable source of supply.

Referring to Fig. 2, the humidifier of the present invention comprises a shallow basin-like receptacle [0, usually a metallic casting (although moulded synthetic plastic is sometimes desirable), having a cylindrical side wall i! provided with screw-threaded holes l2 and I3 to receive the ends of the supply and overflow pipes, respectively. The upper part of the side wall is provided with spaced upstanding lugs ll providing between them the large windows M constituting air inlet openings.

At the center of the receptacle the latter is provided with an annular upstanding wall l5, usually integral with the bottom of the receptacle, defining a central well I6 to which fluid from the main body of the receptacle may flow through openings I! in the lower part of the wall [5.

A bottom casing member I'l, usually of sheet material, is supported on the upper edges of the lugs I l As shown in Fig. 6, the part of the lower casing members ll rests upon the upper edges of the lugs i l the material of the bottom casing member then extending vertically down and then horizontally inward at [8 and then extending downwardly and inwardly to form the truncated, conical, annular guard member $9, the lower edge of which terminates in a plane approximately midway of the height of the windows I4, the large opening bounded by said lower edge defining a passage for air.

The upper part of the bottom casing member I1 is shaped to provide a cylindrical flange within which is snugly fitted the lower part of the upper casing member 2!, usually of sheet metal, tapering upwardly and terminating at its upper end in a cylindrical annular flange portion 22 defining the axial delivery opening 23. As illustrated in Fig. l, a discharge elbow 23 may be fitted into the flange 22. This elbow is rotatable with respect to the casing 2| so as to provide for adJustment of the direction of vapor delivery, if desired. However, the elbow 24 may be omitted so that the vapor-laden air will be discharged directly upward through the Opening 23.

A cover member 25 (Fig. 3), usually of sheet metal, is arranged above the receptacle Ill, the cover comprising the flat horizontal central portion 26 and having the cylindrical downwardly depending skirt portion 21 whose lower edge 28 rests upon the horizontal portion I8 of the bottom casing member H. The part 26 of the cover constitutes a support for the motor M which is arranged with its shaft vertical. This motor has a heavy base plate 29 (Fig. 2). Three cushion members are interposed between the base plate and the upper surface of the part 26 of the cover, and depending pins 30 fixed at their upper ends in plate 29 pass down loosely through openings 3| in the part 26 (the latter being imperforate except for these openings and the central opening which receives the motor shaft), thus providing a three-point suspension for the motor, as more fully described in the patent to Mills, No. 1,604,- 295, dated October 26, 1926.

The shaft 32 of the motor extends down through a central opening in the part 26 of the cover and is fixed within an axial bore 33 in the hub 34 of the water-lifting cone 36. This hub 34 is integral with the depending, downwardly tapering, truncated conical, water-lifting cone 36. Preferably, though not necessarily, the outer surface of this cone 36 is provided with helical grooves 31 to assist in lifting the water from the reservoir, as more fully described in the patent to Mills, No. 1,537,650, dated May 12, 1925. The atom'izing disk 35, having a, central aperture for the reception of the hub 34, is secured to the upper surface of the cone 36, for example, by pins or screws. This disk may be of metal, but is preferably of a plastic material which is not corroded by the liquid. If the atomizing disk be of a plastic material, it is preferably of the order of inch thick. Preferably this disk is flat, having smooth, parallel, horizontal upper and lower surfaces.

Preferably a sleeve 38 is fixed within the lower part of the bore 33, the upper edge 33 of this sleeve constituting a stop for the lower end of the motor shaft. The sleeve 38 may have a drive fit in bore 33 and is of such length that the stop shoulder 39 is at a predetermined definite distance from the lower surface of the disk 35. Thus, when the parts are assembled and with the motor supported on the cover, and with the hub 34 pushed up onto the motor shaft until the shoulder 39 engages the lower end of the shaft, the lower surface of the disk will necessarily lie in a predetermined plane with reference to the lower edge 28 of the cover.

The cylindrical skirt portion 21 of the cover is vertically slitted (but leaving a ring of the material intact above and below the slits) and the metal intervening between the slits is twisted at top and bottom to provide the atomizing vanes 40 (Figs. 1 and 5) These vanes are spaced apart and define the side walls of passages 4| extending outwardly from the interior of the cover and through which the moisture-laden air is expelled. As illustrated in Figs. 3 and 5, the metal which joins the vanes 49 to the parts 21 and 28 is so twisted that the outer edges E of the vanes are spaced from the outer peripheral surface S of the skirt 27, while the inner edges of the vanes are likewise spaced from the inner peripheral surface S of the skirt. Preferably the vanes extend outwardly beyond the surface S a distance of approximately inch and are of a radial width of approximately /4 inch and extend inwardly beyond the surface S approximately inch, The inner edges of these vanes are spaced fromthe outer edge of. disk 35 a distance .P which varies withthesi'zejof the apparatus, ashereiafter more fully described. As shown irrFig; 5 each vane. is substantially fiat'throughout. its effective length, although each,vaneisintegrally' joined" at its upper andlower'ends respectively,

to. the parts 2 and 28" by a twist'edportion of:

the metal.

Each vane Ml is disposed at an angle. to aradiali line drawn through the vertical inner edge'42 "Of that face of" the. vane which isimpinged by the liquid centrifugally expelled'by the disk, rotating injthe direction of the arrow B (Fig; i), as illus trated. in Fig. 5, this angle beingthe angle A between the surface of. the vanea'nd th radial lineX-Y.

To the undersurfaceof the disk 35' air=impe'llingbladesdS (Fig. 1-) are secured. Theseblades may. vary innumber according to th sizeiof the apparatus, for example from;3jto 6. These blades may. be of sheet metal or they may be. integral with the disk ii the latter-be of. a molded plastic. As. illustrated, eachibla'de makes an acute. angle with a radius'through' its outer corner'd l. This. angle 13 (Fig. 4.) between the plane of theblade andi'a radial line T W may. for example be 20; although it may vary, in accordance with the size. of 'theapparatus, from 20 to 27; for-example:-

Specific examples of desirable dimensional relationships, but without intent'to1imitthe:inven'- tion'thereby, are given in the following table:

P'= the. distance between the inner edges'of the'vancs40 and the outer edge of the disk 35.v

the-outer. casing member zljdefining; anannular, upwardly converging chamber 4-7. leading;- to :the.

delivery opening 23.

When the device: is operated, assumin that liquidiisin the lower partof the-receptacle lfi,

theirotationsof theconetfi draws liquid=up and.

distributes it onto'the undersurfaceof the disk.

35. The rapid rotation'oithe-latter, .for example at a speed of theorder. of. from 3,000 to; 3,500

R. P. M=, causes the film of liquid. to move: out centrifugally, gradually getting thinner and thinnerv until it. flies off from: the edgeof. the disk. at. very high velocity and. impacts. the. surfaces .oif

the vanes Mi,- whereby it is broken .down into: fog;

or vapor. The-rotation" of. the. blades 63 creates. astrong. and powerful current of air which picks up the vapor and-:s-weepsit out through the IpasP- sages 5L Since thesezpassages' aresof substantial. length, they are effectivein insuringa-directiom of. delivery; such that theescaping vaporeladen' air. islsubstantially. freed from the; drag efieet of the. rotating. dislnandshowslittle. tendency to. swirl within the chamber 41; Apparently it moves.- almost; vertically: through the chamber. 4.7,,the individualstreams deliveredifrom the passages 4i merging as they approachtheopening, 23. Apparently. butv little friction is. developedlbetween the. flowing. moisture-laden. air andthe walls of the passage. 47,..as comparedwith prior devices in which. the..moisture-laden air takes up arapid swirling action. The. moisture-laden air thus. emergessmoothly andfatsub'stantial velocity and with no. observable. tendency to rotate or. swirl. Although the. apparatusoperates at. highspeed, very little noise can. be discerned; From the. opening23; a smoothlefiowing, substantially uni.- form. current. ofmoisture-laden air. moves upwardly' in a substantially vertical direction. and. substantially devoidof any swirling action.

, This smoothlyflowing. stream, whose energy isnot dissipated by the" internal friction resulting from swirflsor eddies, is projected much further. from the orifice 23 thanwould-be true if thecurrent were of .a. swirling. irregular nature. Thus the vapor. of; fog is.broughtl into contact with a 1 very large volumeof. air with, consequentopti.

mum. moistening. effect. Moreover, because. of this rapid and unimpeded flow the amount. of water convertedintofogpr. vapor. is greatly in. creased, as compared with. that resultant. from the. operation of apparatus in. which the flow. is. impeded by frictiomso that it becomes possible. to deliver large quantities ofwater in vapor form. by the use of apparatus .off relatively small dimensions.

Not only isthe apparatus useful. formoistening the. air, but it is alsov useful in distributing medicament's, germicides or odor dispellants. When designed for suchlpurposes the partswhich contact. the liquid'or. vapor should'be unaifcted by the substances employed; for. example, they may be of asynthetic plastic, 0r metal coated with enamel.

While one desirableembodiinent'of'the invention has been .describedby, way of" example, it is to be understood'th'at theinvention is broadly inclusive of alll'modifications, falling. within the scope of the appendedi'claiins.

IcIaiins.

1f. Humidifying. apparatus of. the kind having: incombination.areceptacle for liquid, a circular, substantially. flati' disk rotatable, about a vertical axis, a. downwardly-tapering conical feed. boss depending from. the center of the disk into the liquid inthereceptacle, a stationary cover. memberarrangedabove. the. disk, the cover member constituting: a.S11I l3ori1-forv a motor, said cover member having a. cylindrical, depending skirt portion:of;an'internalldiameter. greaterv than .that of thedisk andwhose lower edge is below. the plane-of thelower. surface of the disk, said cylindrical: skirt portion havinga multitude of delivery passages therethrough; whose walls are defined by, fixed, immovable, substantiallyfiat vanes constituting integral parts. of said. skirt. portion, meansrbeneath the =disk-operative to. discharge air out through said passages, anda motor. for. rotating the disk at--high,.-ve1ocity, characterized in thatthevanes-areso arranged as toprovide de-- livery passages havingside walls which terminate outwardly beyond. theouter. peripheral surface of theskinai'that' side. wall-of each passage which is opposed. to :the. direction of rotation of the. disk and. which. is impinged by liquid, centrifugally expelled from: the disks-being inclined at. an angle of. from. 33"t0, 10 tothat radialeplane. of. the. disk.

7 which intersects the inner vertical edge of said wa 2. Humidifying apparatus of the kind having in combination a receptacle for liquid, a circular, substantially flat disk rotatable about a vertical axis, a downwardly-tapering conical feed boss depending from the center of the disk into the liquid in the receptacle, a stationary cover member arranged above the disk, the cover member constituting a support for a motor, said cover member having a cylindrical depending skirt portion of an internal diameter greater than that of the disk and whose lower edge is below the plane of the lower surface of the disk, said cylindrical skirt portion having a multitude of delivery passages therethrough whose walls are defined by fixed, immovable, substantially flat vanes, air-impelling blades below the disk operative to discharge a current of air outwardly through said passages, and a motor for rotating the disk at high velocity, characterized in that the vanes extend both inwardly and outwardly from the annular skirt portion, that face of each vane which is opposed to the direction of rotation of the disk and which is impinged by the liquid centrifugally expelled from the rotating disk being inclined at an angle of from 3 to to that radial plane of the disk which intersects the inner vertical edge of said face, the outwardly projecting portions of the vanes being of the order of inch in horizontal width measured outwardly from the outer surface of the skirt.

3. Humidifying apparatus of the kind having in combination a receptacle for liquid, a substantially flat disk rotatable about a vertical axis, a downwardly-tapering conical feed boss depending from the center of the disk into the liquid in the receptacle, a stationary cover member arranged above the disk, the cover member constituting a support for a motor, said cover member having a cylindrical depending skirt portion of an internal diameter greater than that of the disk and whose lower edge is below the plane of the lower surface of the disk, said cylindrical skirt portion havin a multitude of delivery passages therethrough whose walls are defined by fixed, immovable, substantially fiat vanes constituting integral parts of said skirt portion, fan blades attached to the under side of the disk and which are operative to discharge air outwardly through said passages, and a motor for rotating the disk at high velocity, characterized in that the vanes extend both inwardly and outwardly from the annular skirt psrtion, that face of each vane which is opposed to the direction of rotation of the disk and which is impinged by the liquid centrifugally expelled from the rotating disk being inclined at an angle of from 3 to 10 to that radial plane of the disk which intersects the inner vertical edge of said face, the outwardly-projecting portions of the vanes being of the order of inch in horizontal width measuring outwardly from the skirt portion and the inner portions of the vanes being approximately A; inch in horizontal width measured from the inner periphery of the skirt portion.

4:. Humidifying apparatus of the kind having in combination a receptacle for liquid, a circular, substantially flat disk rotatable about a vertical axis, a downwardly-tapering conical feed boss depending from the center of the disk into the liquid in the receptacle, a stationary cover member arranged above the disk, the cover member constituting a support for a motor, said cover member having a cylindrical depending skirt portion of an internal diameter greater than that of the disk and whose lower edge is below the plane of the lower surface of the disk, said cylindrical skirt portion having a multitude of delivery passages therethrough whose walls are defined by fixed, immovable, substantially fiat vanes, a fan beneath the disk and rotatable therewith, said fan being operative to discharge air outwardly through said passages, and a motor for rotating the disk at high velocity, characterized in that each vane is inclined at an angle of between 3 and 10 to that radial plane of the disk which intersects the inner vertical edge of the face of the vane which is opposed to the direction of rotation of the disk and which is impinged by the liquid which is centrifugally expelled by the rotating disk.

5. Humidifying apparatus of the kind having in combination a receptacle for liquid, a circular, substantially flat disk rotatable about a vertical axis, a downwardly-tapering conical feed boss depending from the center of the disk into the liquid in the receptacle, a stationary cover member arranged above the disk, the cover member constituting a support for a motor, said cover member having a cylindrical depending skirt portion of an internal diameter greater than that of the disk and whose lower edge is below the plane of the lower surface of the disk, said cylindrical skirt portion having a multitude of air and water passages therethrough whose walls are defined by fixed, immovable, substantially flat vanes constituting integral parts of said skirt portion, a motor for rotating the disk at high velocity, and a plurality of fan blades fixed to the underside of the disk, the blades being disposed symmetrically about the axis of the disk, characterized in that each vane is inclined at an angle of approximately 6 to that radial plane of the disk which inter sects the vertical inner edge of the face of the vane which is opposed to the direction of rotation of the disk and which is impinged by the liquid centrifugally expelled from the disk.

6. Humidifying apparatus of the kind having in combination a shallow basin-like receptacle for liquid, said receptacle having an upstanding side wall provided with air ingress apertures, a casing comprising an annular bottom member supported on the side wall of the receptacle, the casing also comprising an upper part whose lower margin removably fits the outer part of the bottom member of the casing, the upper part of the casing tapering upwardly and terminating at a delivery orifice, a circular, substantially flat disk located in a plane just above the plane of the top of the receptacle wall, said disk being rotatable about a vertical axis, a feed boss depending from the center of the disk into the liquid of the receptacle, a stationary cover member arranged above the disk, the cover member constituting a support for a motor, said cover member having a cylindrical, depending skirt portion of an internal diameter greater than that of the disk and whose lower edge is below the plane of the lower surface of the disk, said cylindrical skirt portion having a multitude of passages therethrough whose walls are defined by substantially fiat vanes constituting integral parts of said skirt portion, a motor for rotating the disk at high velocity, an inner casing having its lower portion telescoped over the upper part of the skirt portion of the cover, the inner casing housing the motor and being spaced from the upper part of the outer casing to provide an annular chamber leading from the vanes to the delivery orifice. said outer chamber-- REFERENCES CITED The following references are of record in the file of this patent:

I Number 10 UNITED STATES PATENTS Name Date Mills Dec. 19, 1922 Cutler Jan. 28, 1930 Mills June 30, 1931 Mills July 28, 1931 Cutler Dec. 8, 1931 Cramer Mar. 15, 1932 Anthony. Jr Oct. 23, 1934 

